Preparation,recognition And Characteristics Of Hepatoprotective Component Of Silybin Molecularly Imprinted Polymer By Reverse Atom Transfer Radical Precipitation Polymerization

Silybin is an active ingredient extracted and purified from the dry fruit of composites medical plants Silybum Marianum.It has pharmacological actions of resisting liver fibrosis,protecting liver cell membrane,improving liver function and others.In addition,the recent studies have shown that silybin also has the effects of anti-lipid peroxidation,scavenging oxygen free radical activity,anti-tumor,lowering blood lipids,reducing cardiac toxicity and so on.However,there are many defects in the extraction of silybin from Chinese herbal medicine silymarin seed using traditional extraction and separation techniques.This paper use reverse atom radical transfer polymerization method to prepare the magnetic silybin molecular imprinted polymer?S-MIP?;and studied the structure characterization and adsorption properties of the prepared magnetic silybin molecular imprinted polymer;then extract and separate the silybin from the extract of silymarin seed by S-MIP finally.The main contents of this paper are as follows:?1?Using simulation techniques to calculate the binding energy between silybin and three functional monomers MAA,MAAM,and AAM,According to the calculation results,MAA was the most suitable functional monomer.Then the experiment also proves that imprinted material with the largest adsorption amount is prepared by MAA as functional monomer.So MAA has been selected to be the best functional monomer in the preparation of silybin's imprinting system.Using simulation technique,silybin and MAA are calculated in solvents such as acetonitrile,methanol,toluene and DMSO,and the solvation energy can be ranked as:DMSO>ACN>MeOH>Toluol.However,when MIPs was prepared,it is interfered by other factors,and the adsorption capacity of imprinted materials prepared in different solvents is ACN>DMSO>MeOH>Toluol,and finally ACN is selected as the best polymerization solvent.?2?Exploring the optimum preparation conditions of S-MIP by using orthogonal experimental method.Finally,the experimental results show that the optimal conditions for the synthesis of S-MIP are as the following:ACN 10 mL,MAA 0.25 mmol,EGDMA 3 mmol,Fe₃O₄&SiO₂-MPS 100 mg;and the adsorption capacity of S-MIP prepared under this condition can reach 7.19 mg g^-1.?3?Characterizing the structure,morphology,crystal and thermal stability of magnetic particles by using FT-IR?SEM?XRD?VSM?TGA.?4?The optimum adsorption conditions,adsorption model,selective adsorption performance and reusability of S-MIP are studied.Under the optimum conditions of solid-liquid ratio of 20/5?w/v,mg/mL?,initial concentration of 0.08 mg mL^-1and adsorption time of 420 min,the adsorption of silybin by S-MIP is 7.19 mg g^-1.The results of scatchard curve analysis show that there are different binding sites on S-MIP,and they have specific adsorption capacity for template molecules.The pseudo second order reaction model can explain the adsorption process of S-MIP better.It is concluded that S-MIP has strong selectivity and competitive adsorption capacity from the experimental study on selective adsorption performance.In the repeated experiments,the saturation adsorption capacity of S-MIP only decreases by 15.8%after five adsorption-desorption experiments,which indicates that the magnetic silybin molecular imprinted polymer that we prepared has the good stability and reproducibility.?5?S-MIP is simply applied to the extraction and purification of the active ingredients of Chinese herbal medicine Milk Thistle.The experimental results show that adsorption capacity of S-MIP still can up to 1.32 mg g^-1,and the imprinted factor is 3.219.This further demonstrates that the prepared silybin magnetic molecular imprinted polymer has an efficient selection capability for silybin,and has the ability to isolate and extract silybin.